Ashley Ahearn

International leaders gathering in Paris to address global warming face increasing pressure to tackle the issue of "climate refugees." Some island nations are already looking to move their people to higher ground, even purchasing land elsewhere in preparation.

In the U.S. Northwest, sea-level rise is forcing a Native American tribe to consider abandoning lands it has inhabited for thousands of years.

Across the Western U.S., yearly areas of snowpack are decreasing, and researchers are trying to figure out what that means for everything that relies on the snowmelt — from farms to power plants to a little creature known as the Cascades frog.